JP4038239B2 - Ferrierite, crystalline aluminosilicate, ferrierite hydrogen, process for producing them, and process for structural isomerization of linear olefins - Google Patents

Abstract

Ferrierite is prepared by a method that provides extremely pure crystalline material. The method consists of preparing a mixture of silica, alumina, alkali metal and pyridine of a certain composition and heating said mixture to form the crystals. The SiO2/Al2O3 and OH<->/SiO2 are controlled to insure preparation of high SiO2/Al2O3 ratio, high surface area and high purity ferrierite. An olefin skeletal isomerization catalyst is prepared from a high silica to alumina ratio, high surface area and high purity ferrierite.

Description

選択性は次の通りに計算される：

そして収量は次の通りに計算される：

表１に上記の実施例において調製した幾つかの触媒を試験して、得られたオレフィン骨格の異性化の作用の結果を示す。この表に異性化試験における触媒の走行ライフ、即ち走行開始の時間から、ピーク濃度に到達した後生成物中のメチル分枝オレフィン（これらの試験ではイソブチレン）濃度が36wt%に減退するまでの時間を示している。試験した触媒の幾つか（実施例１４及び１５）は、この高い生成物中のイソブチレン濃度には決して到達しなかった。本発明の触媒は、最も長い走行ライフを達成することが可能であった。長い走行ライフを持続し、そしてある場合には触媒の再生によってむしろ増加した。
商業的操作においては、触媒を再生する前、生成物中のイソブチレンの濃度が20wt%以下に減退するまで、触媒を作用させることが望ましい。実施例１に記載の方法で調製したサンプルは、生成物中イソブチレン含有量が20wt%に低下するまで走行させた場合、603時間の走行ライフを示した。より長い走行ライフはまた、1-ブテンの低い毎時重量空間速度、WHSVで作用させることによって達成することができた。走行ライフの増加はまた、供給材料中のオレフィン含有量を、しばしばオレフィン骨格異性化の供給材料中に存在する反応性の少ないガスを用いて、希釈する事によっても得ることができる。適当な希釈ガスとしては、例えば、プロパン、ブタン、ペンタン、窒素、水素を含む。これらのガスの使用は異性化されるオレフィンの分圧を下げることに役立ち、そして分枝オレフィンへの高い報告された選択性をもたらす。希釈ガスの使用は、本発明の触媒の走行ライフとイソブチレンへの選択性を増加させることができるけれども、希釈ガスの存在は、DE-A-3,000,650及びUS-A-5,043,523で報告されている種類の非-フェリエライト触媒についての報告以上に、一定の転換率での長い走行ライフ、及び高い選択性を得ることを要求されていない。
表１はまた、40%転換率、45%転換率、及び50%転換率での各種触媒の選択性、そして試験の間の生成物中のイソブチレンの最高濃度（重量パーセント）を示している。
表１から分かる通り、本発明の触媒（実施例１、３及び１７）は、低いシリカとアルミナのモル比（実施例１４、１５）、そして/又は低い表面積（実施例１５及び１６）を有するサンプルと比較するとき、一定の転換率のレベルで最高の選択性が、そして最高の生成物中のイソブチレン濃度が得られている。表１は高い表面積を示し、高純度の、高いシリカとアルミナモル比のフェリエライトで作られた触媒によって得られる、オレフィン骨格の異性化の作用に著しい改良を与えていることを明らかに示している。実施例３で作られた触媒は、40%転換率で95%のイソブチレンの選択性を得ている。殆ど100%の選択性は、僅かに低い転換率レベルで本発明の触媒を用いて得られた。
実施例３は、45%転換率でこの試験条件で88%のイソブチレンへの選択性を得た。低いシリカとアルミナのモル比のフェリエライトで作られた触媒（実施例１５及び１４）は、45%転換率で68%及び70%のイソブチレンへの選択性を達成した。高いシリカ/アルミナのモル比のフェリエライトで作られた実施例１６の触媒は、これは326m²/gの表面積を持っており、45%転換率で79%のイソブチレンへの選択性を達成した。本発明によって調製された触媒は、全て45%の転換率で83%以上のイソブチレンへの選択性を示した。
本発明によって調製された高純度、高シリカ/アルミナモル比のフェリエライトの作用の利点とするところは、実施例１７で作られた触媒のような押出し触媒に対し、より少ない総フェリエライトを含むように結合剤で希釈した場合（実施例１７）ですら、実施例１４、１５、及び１６を凌ぐ優れた性能を可能とすることにある。これら作用の長所とする点は、このフェリエライト触媒を多数回再生しても維持されていた。
実施例で調製された結晶フェリエライトサンプルは、透過型電子顕微鏡、TEM、走査型電子顕微鏡、SEMを用い、21,200X倍率と同程度の高い倍率で解析した。図１は実施例１の方法で調製したフェリエライトのTEM顕微鏡写真である。顕微鏡写真は21,000X倍率で撮影した。本発明のフェリエライト結晶は、モルホロジー（morphology）的に輪郭を良好に示す小平板の形式を示しており；結晶の１つの寸法は約0.1μmの平均直径を持っている。二番目に大きい直径の平均は約0.8μmであり、最も大きい直径の平均は約1.1μmである。実施例１で調製された結晶の幾つかは約2μmの最大の直径を持っていた。
本発明において作られたフェリエライトのモルホロジーは、実施例１４で作られたフェリエライトのモルホロジーとは異なった形態であり、実施例１４のフェリエライトはより小さく、更に丸く、そして不規則な結晶のようにに見える。図２は実施例１４の方法で調製されたフェリエライトのTEM顕微鏡写真である。顕微鏡写真は21,200X倍率で撮影した。実施例１４で作られたフェリエライト結晶の最大直径の平均は、約0.2μmであった。結晶の幾つかは、3つの寸法全てが、約0.1μm又はそれ以下であった。
本発明で調製されたフェリエライトの結晶モルホロジーはまた、US-A-3,392,466の方法で調製されたミクロクリスタリンZSM-35（フェリエライトのイソタイプ）のそれとは異なっている。ミクロクリスタリンZSM-35は、0.005μm〜0.1μmの範囲の直径を有する非常に小さい粒子が存在すると報告されている。
本発明における結晶の比較的大きい小平板状モルホロジー、フェリエライトの高表面積、及び高シリカ/アルミナモル比は、これら高純度フェリエライト触媒が、ブチレン含有供給材料を処理する場合に固定の転換率レベルでイソブチレンに対し優れた選択性を示すことを可能にしている。これら同一のフェリエライトの特質は、触媒が他のＣ4〜Ｃ10のオレフィンを含む供給材料とも同様に良く働くことを可能としている。

Technical field
The present invention provides high SiO₂/ Al₂O_ThreeThe present invention relates to a novel ferrierite having a high ratio and a high purity, a process for producing the same, and an improved olefin isomerization catalyst prepared from the ferrierite.
Technology background
Ferrierite is a crystalline aluminosilicate and has been found to be useful as an adsorbent, catalyst or catalyst support. For example, the synthesis of ferrierite and ferrierite-type materials, such as ZSM-35, is well known (eg, Journal of Catalysis, Vol. 35, 256-272 (1974) and US-A-3,933,974; 3,966,883 ; 3,992,466; 4,016,245; 4,088,739; 4,107,195 and 4,251,499). For example, it can be prepared by heating an aqueous mixture of alkali and / or alkaline earth metals, alumina and silica.
These synthetic methods have several drawbacks. In general, a long time and a high temperature are required. High temperatures that promote crystallization require a pressurized vessel. Product SiO₂/ Al₂O_ThreeThe molar ratio is relatively low, generally less than about 30 and the product is 350 m²Indicates a surface area of less than / g.
Some of these difficulties are partially overcome by using organic nitrogen compounds, commonly referred to as templates. Short crystallization times and low synthesis temperatures can be obtained by using a variety of such templates (see, for example, US-A-4,000,248; 4,107,195; 4,251,499; and 4,795,623). Even with these methods, high SiO is particularly desirable for many catalytic applications.₂/ Al₂O_ThreeDoes not give ferrierite with a high ratio and high purity.
Many of the organic nitrogen compounds proposed as templates are expensive and difficult to store and use. Many of these compounds have pKa values between 7 and 12, as disclosed in US-A-4,205,053. Pyridine has a pKa of 5.29, but seems to be somewhat complicated to use for zeolite synthesis. For example, US-A-4,797,266 shows that a preparation process involving pyridine gives a mixture of zeolite ZSM-5 and ferrierite. US-A-4,613,488 shows that the use of pyridine or certain derivatives results in a new aluminum silicate that is not ferrierite. US-A-4,578,259 uses pyridine and “non-pyridine” nitrogen-containing compounds, or pyridine and oxygen-containing compounds, to create “ISI-6” (the same shape as ferrierite, Atlas of Zeolite Structure Types, Meier and Olson , Butterworths-Heinemann, 3rd revised edition, 1992, p. 98). According to US-A-4,578,259, the use of pyridine alone does not lead to the formation of ferrierite.
US-A-4,251,499 teaches the use of piperidine and alkyl-substituted piperidines as templates. As a comparative example, the use of pyridine as a template in Example 12 gave a product containing 50% ferrierite, 30% other zeolitic material, and 20% amorphous material.
In EP-A-501,577, Example 2, a ferrierite catalyst having a molar ratio of silica to alumina of 72: 1 is 93.5 SiO₂/1.0 Al₂O_Three/7.4 Na₂O / 19.6 Na₂SO_Four/30.0 pyridine / 1938 H₂Prepared from a reaction gel having a molar composition of O; OH in the reaction gel^-/ SiO₂The molar ratio of was 0.16.
EP-A-523,838 is 326 m in Example 4.²discloses a ferrierite catalyst having a silica to alumina molar ratio of 87: 1 with a surface area of / g.
It is an object of the present invention to provide a process for producing highly pure ferrierite having a high surface area and having a high silica to alumina molar ratio. , Remarkably excellent catalyst behavior.
Disclosure of the invention
Very high SiO₂/ Al₂O_ThreeAn exceptional crystalline phase purity ferrierite powder having a ratio of: can be produced by forming an aqueous mixture of silica, alumina, alkali metal and pyridine and heating the mixture until the aluminosilicate is crystallized. it can. Various parameters must be controlled to provide high ratio, high purity, high surface area materials. Synthetic gels must contain a limited amount of alkali metal, OH^-/ SiO₂The molar ratio must be within a limited range and sufficient pyridine must be present to facilitate the reaction.
An important aspect of the method of the present invention is the high SiO₂/ Al₂O_ThreeIn contrast to the prior art, which gives a molar ratio of ZSM-5, this method is notable for other crystals such as zeolite ZSM-5, mordenite, magadiite, various overlay materials, and quartz as an impurity. It is to provide ferrierite without forming a sex substance.
Furthermore, the present invention is to provide a catalyst for the structural isomerization of linear olefins of at least 4 carbon atoms into the corresponding methyl-branched isoolefins, made by a previously reported method, Compared to catalysts containing ferrierite with lower silica to alumina molar ratio and / or lower surface area, the catalysts of the present invention have higher selectivity at a fixed conversion, longer running life, and higher concentration. Figure 2 shows improved isobutylene yield in olefin fluid processing.
Detailed Description of the Preferred Embodiment
Ferrier light
The method of the present invention requires the use of a synthetic mixture of a specific composition. Silica, alumina, alkali metals, pyridine, and optionally aqueous sources of acids or acid salts are used. The silica source is typically an alkali metal silicate, silica sol, a readily soluble silica gel or precipitate. The alumina raw material is generally sodium aluminate, aluminum sulfate or a mixture of alumina and caustic soda. In addition to the alkali metals contained in the silica and alumina raw materials, alkali metal hydroxides and alkali metal salts can also be used. If it is necessary to reduce the alkalinity of the synthesis mixture, a mineral acid can be added. Pyridine is used as the crystal structure directing compound or template. In the absence of seeding the synthesis mixture with ferrierite, to give the desired product with a high silica to alumina molar ratio, high purity, and high surface area, the synthesis mixture has the following molar composition: Should:
Al₂O_Three: 60-500 SiO₂: 18-40 Pyridine: 1.5-4 M₂O: 950-2000 H₂O
Where M is an alkali metal, usually sodium.
If the synthetic mixture is inoculated with ferrierite (Example 12 and later), the molar composition of the synthetic mixture is:
Al₂O_Three: 60-500 SiO₂: 10-40 Pyridine: 1.5-4 M₂O: 950-2000 H₂O
Can be.
Accordingly, the present invention provides a method for producing ferrierite crystalline aluminosilicate,
providing a mixture containing alkali metal, silica, alumina, and pyridine raw materials, the mixture having the following composition in moles:
Al₂O_Three: 60-500 SiO₂: 10-40 R: 1.5-4 M₂O: 950-2000 H₂O
R is pyridine, M is alkali metal and the raw material of the alkali metal, and silica is 0.05 to 0.15 mol of OH for each mol of silica^-There is something like that.
b. heating said mixture at a temperature of 140-180 ° C; and
c. Collecting ferrierite
It is characterized by comprising.
And on top of that, the present invention shows the X-ray diffraction pattern of ferrierite, and in the anhydrous state,
1-3 R: 0.5-0.9 M₂O: Al₂O_Three: 40-500 SiO₂
(R is pyridine, and M is an alkali metal) at least about 350 m²It is to provide a crystalline aluminosilicate having a surface area of / g and being essentially a ferrierite crystalline phase.
The amount of silica in the mixture is the desired SiO₂/ Al₂O_ThreeIt must be relatively high to make a ratio. M₂O amount, usually Na₂The amount of O must be limited as well. If the amount of alkali metal is too high, the purity of the product will decrease even if all other conditions are maintained. Additional requirements include SiO₂/ Al₂O_ThreeWhen producing products with a molar ratio of 40: 1 to 70: 1, preferably 50: 1 to 70: 1^-/ SiO₂Is that the mole of must be between 0.05 and 0.15. SiO greater than 70: 1₂/ Al₂O_ThreeOH for molar ratio products^-/ SiO₂Must be between 0.05 and 0.11. Hence, 0.05-0.11 OH^-/ SiO₂Can be used to make any ferrierite crystalline aluminosilicate of the present invention and having a silica to alumina molar ratio of at least 40: 1, preferably at least 50: 1. OH greater than 0.11 and up to 0.15^-/ SiO₂For this ratio, only ferrierite with a silica to alumina ratio of 70: 1 or less is produced. If less OH^-If is present, crystallization will not proceed well. If more OH^-If present, the ferrierite product is impure and its usefulness is greatly reduced for many catalytic applications, such as olefin skeletal isomerization of light olefins such as butene and pentene. End up.
The synthesis mixture can be prepared by mixing the aqueous reactants until relative homogeneity is obtained. The mixture can be heated immediately or aged for some time. Heating is generally carried out for about 12 to 72 hours, generally under pressure at about 140 ° C. to 180 ° C. until crystallization is complete. These conditions are different from many conventional ferrierite synthesis methods because the time required for crystallization is shorter and the temperature at which crystallization occurs is lower.
The addition of ferrierite to the synthesis mixture can employ less pyridine requirements, and still obtain a high silica to alumina molar ratio, high purity, high surface area ferrierite at 170 ° C for 24 hours. It is done. The type of ferrierite added to the synthesis mixture as seed ("ferrierite seed") is preferably a high silica to alumina molar ratio, high purity, high surface area ferrierite made by the process of the present invention. However, other types of ferrier lights can also be used. Seeding the synthesis mixture with low purity ferrierite results in poor ferrierite products and / or non-ferrierite contaminants as described above. Useful amounts of ferrierite are generally about 0.001, preferably about 0.1 to about 50, preferably about 10% by weight of the anhydride of the synthesis mixture.
In crystallization, ferrierite separates the liquid from the mother liquor, for example, by filtration or by centrifugation, and is generally washed, dried (at a temperature of about 100-200 ° C), and optionally calcined at a temperature of about 200 ° C or higher. And recovered.
The product is ferrierite containing no additional crystalline zeolitic material (not crystalline impurities). The isotypic skeletal structure of ferrierite is determined by X-ray crystal diffractionSometimes it exists in a single crystalline phase. Atlas of Zeolite of Structure Types, loc.cit.Please refer to. A prominent framework feature of ferrilite isomorphic structures found by X-ray crystallography lies in the parallel channels in the aluminosilicate skeleton, which is roughly elliptical in cross section. Examples of such zeolites with a ferrierite isomorphic framework include ferrierite (orthorhombic or monoclinic), Sr-D, FU-9 (EP B-55,529), ISI-6 (US-A- 4,578,259), NU-23 (EP-A-103,981), ZSM-35 (US-A-4,016,245), and ZSM-38 (US-A-4,375,573), ie "essential ferrierite crystal phases".
The generated ferrierite is each Al₂O_ThreePreferably about 50 moles or more, more preferably 60 moles or more, most preferably 65 moles or more, preferably up to about 500 moles, more preferably up to 200 moles of SiO.₂,including. The composition in the anhydrous state is preferably:
1-3 R: 0.5-0.9 M₂O: Al₂O_Three: 50-200 SiO₂
Where R is pyridine and M is an alkali metal.
The surface area is at least about 350m²/ g, preferably at least about 370 m²/ g, about 450m²up to / g. In general, it has the form of a small plate, one dimension of the crystal is very small, an average of about 0.2 μm or less (thin), generally about 0.1 μm, and the other two dimensions are larger, generally It has an average of about 0.6 μm to about 2 μm. This ferrierite is suitable for use as a catalyst or support in many hydrocarbon conversion processes such as catalytic dewaxing. It has been found that an improved olefin skeleton isomerization catalyst can be obtained by using this ferrierite.
Olefin skeleton isomerization catalyst
The ferrierite of the present invention is preferably converted to ammonium ferrierite by ammonium ion-exchange and optionally calcined to substantially hydrogen form ferrierite (see, eg, US-A-4,251,499,4,795,623, and 4,942,027). In other words, it produces “ferrierite-hydrogen”. For example: d) removing at least a portion of pyridine by heating to a temperature of about 500 ° to about 625 ° C. to obtain calcined ferrierite; e) contacting the calcined-ferrierite with an ammonium ion source To give an ammonium-ion exchanged ferrierite and f) calcining the ammonium-ion exchange ferrierite at a temperature of about 200 ° C to 700 ° C.
The catalyst comprises the ferrierite described above, optionally a binder and a metal that promotes coke-oxidation, such as palladium and / or platinum. In order to obtain high selectivity at fixed conversion, greater run life, and improved isobutylene yield in high olefin fluid processing, the catalyst is essentially a ferrierite crystalline phase and Al₂O_ThreeAbout 50 moles or more, preferably 60 moles or more, most preferably 65 moles or more, preferably up to 500 moles of SiO.₂And a surface area of at least about 350 m²/ g, preferably at least about 370 m²/ g.
Refractory oxides are useful as binding materials. Suitable refractory oxides include natural clays such as bentonite, montmorillonite, attapulgite, and kaolin, and hectorite; alumina; silica, silica-alumina, hydrated alumina; titania, zirconia, and mixtures thereof. A suitable weight ratio of zeolite to binding material is about 60:40 to about 99.5: 0.5, preferably about 75:25 to about 99: 1 (anhydride basis). Preferably, the binder is alumina.
These suitable binders include silica or any conventional catalyst-preparing alumina-containing binder, such as alumina, silica-alumina, and clay. For the purposes of the present invention, an “alumina-containing binder” includes any alumina precursor, including hydrated forms of alumina, such as bayerite, boehmite, and gibbsite, This is calcined alumina (Al₂O_Three). Preferred silica-alumina is amorphous silica-alumina such as aluminosilicate gels and sols. The binder can be supplied in any convenient form such as a powder, slurry, gel, or sol. When the binder is supplied as a slurry, gel or sol, at least a portion of the water used in the pulverization process can be found as a portion of the slurry, gel or sol.
Preferred binders are pseudoboehmite and alumina such as gamma and bayerite alumina, which are commercially available and readily available. LaRoche Chemical supplies appropriate alumina powders with the alumina family VERSAL® and Vista Chemical with CATAPAL® alumina. The alumina binder is preferably a highly dispersible alumina powder, particularly when extrusion is used, such as CATAPAL D, which is generally Al₂O_Three It is possible to disperse 50% or more in an aqueous dispersion containing 0.4 mg equivalent of acid (acetic acid) per 1 gr.
The catalyst can be prepared in various ways. In one embodiment, ferrierite is formed into pellets by compression or extrusion with a binder, and optionally a catalytic metal is added by impregnating the pellets with a metal-containing solution. After impregnation, the catalyst is heated and calcined. In other embodiments, ferrierite powder and alumina powder are mixed (eg, by mulling) with water and one or more catalytic metal compounds, and the resulting mixture is formed into pellets. Preferably, the pellet is formed by compression. When using extrusion, a peptizer-accelerating acid such as nitric acid, acetic acid, citric acid or mixtures thereof is added to the mixture and a cellulose derivative such as METHOCEL® F4M hydroxypropyl methylcellulose (Dow Chemical). Optional extrusion aids are used. The amount of puffing acid used is an amount that can be readily determined by routine work experimentation and provides a plastic, extrudable material. The term “pellet” as used herein can be any shape or form as long as the material is consolidated. Examples of these shapes include (but are not limited to) cylindrical shapes, two-leaf, three-leaf, four-leaf shapes, gear shapes and spheres, which may or may not have dents. .
The formed pellets are calcined at a temperature of, for example, about 200 ° C., preferably about 300 ° C., more preferably about 450 ° C., for example about 700 ° C., preferably about 600 ° C., more preferably about 525 ° C. The
The mixture should be mixed until completely or vigorously uniform. Mixing can be done by blending all the components of the mixture at once or by sequentially adding the components of the mixture in different mixing steps. Mixing can be accomplished by mulling, that is, adding sufficient water to form a thick paste, and mixing can be accomplished by a powder mixing method involving shearing of the paste. As commercially available muller mixers, for example, Lancaster Mix Muller and Simpson Mix Muller can be used. Commercial blenders such as ribbon blenders, high shear mixers, and / or powder mills can also be used for mixing.
Hydrocarbon feed fluid
The hydrocarbon feed contains at least one linear (or normal) olefin (or alkene) containing at least 4 and preferably 4 to 10 carbon atoms, which has 4 to 10 carbon atoms. Containing a linear alkene segment. It is believed that long chain linear alkenes and compounds containing long chain linear segments can penetrate into the zeolite catalyst to a distance effective to cause isomerization. Thus, it is not required that all molecules are small enough to fit perfectly into the catalyst micropore structure. Preferred suppliers include butylene (or butene) and / or amylene (or pentene).
As used herein, n-butylene includes all forms of n-butylene, such as 1-butene and 2-butene, trans-2-butene, or cis-2-butene, And mixtures thereof. As used herein, n-amylene or n-pentene includes 1-pentene, cis- or trans-2-pentene, or mixtures thereof. Generally n-butylene or n-amylene is used in the presence of other materials such as other hydrocarbons. Thus, the feed fluid containing n-butylene or n-amylene can be other hydrocarbons such as alkanes, other olefins, diolefins such as butadiene and pentadiene, naphthenes, acetylenes, aromatics, hydrogen, And an inert gas. Generally, the n-butene feed fluid used in the present invention contains about 10 to 100 weight percent n-butene. For example, a fractionated hydrocarbon feed fluid from a fluid catalytic cracking effluent generally contains about 20 to about 60 wt% normal butene, and the hydrocarbon effluent from an ether processor, such as methyl-tert-butyl ether (MTBE). The stream generally contains 40 to about 100 WT% n-butylene. The feed fluid from steam cracking and catalyst cracking also contains substantial amounts of alkanes, i.e. up to about 80 wt% alkanes. Olefins obtained by selective hydrogenation of dienes, such as butadiene, can also be used.
Isomerization conditions
In the process of the present invention, a hydrocarbon fluid containing at least one linear olefin is contacted with the catalytic zeolite under isomerization conditions. In general, a hydrocarbon fluid is contacted with the zeolite catalyst in the gas phase at a suitable reaction temperature, pressure, and space velocity. In general, suitable reaction conditions include a temperature of about 200 ° C. to about 650 ° C., preferably about 320 ° C. to about 600 ° C., an olefin partial pressure of about 0.5 atmospheres or more, and a total pressure of about 0.5 to about 10.0 atmospheres or more. 0 to 30 or more hydrogen to hydrocarbon molar ratio (ie, the presence of hydrogen is optional), substantially free of water (ie, less than about 2.0 wt% of the feed), and about 0.5 to about 100 hr.^-1This includes the weight hourly space velocity (WHSV) of hydrocarbons. These reactor fluids can contain non-reactive diluents such as alkanes. Hydrogen can be added directly to the feed fluid prior to introduction of the isomerization zone, or hydrogen can be added directly to the isomerization zone.
The preferred reaction temperature depends on a number of factors such as pressure, weight space velocity per hour, and feed composition. Low molecular weight olefins such as butene are best isomerized at temperatures between 350 ° C. and 650 ° C., while high molecular weight olefins are best isomerized at lower temperatures. Pentene is best isomerized at a temperature of about 200 ° C to 550 ° C, and hexane is best isomerized at a temperature of about 200 ° C to 500 ° C. Mixed butene and pentene are best isomerized at temperatures of about 200 ° C. to 600 ° C., and mixed pentene and hexane are best isomerized at about 200 ° C. to 525 ° C. The use of lower temperatures is a great advantage if the olefin is easily cracked into light and undesirable types at high temperatures. Due to the fact that higher equilibrium concentrations of branched olefins are possible at lower temperatures, it is also possible to achieve the desired product objective at higher temperatures at lower temperatures.
In a typical butene isomerization process scheme, the butene vapor stream is at about 320 ° C. to about 650 ° C., an olefin partial pressure of about 5 psia to about 50 psia, and a total pressure of about 15 to about 100 psia, and about 0.5 ~ 50hr^-1Olefin-based WHSV is contacted with such a catalyst in a reactor. Preferred isomerization conditions are 350 ° C to about 450 ° C, atmospheric pressure, about 2 to about 25 hours.^-1More preferably about 2 to about 15 hours.^-1This is WHSV based on olefins.
In a typical pentene isomerization process scheme, the pentene vapor stream is about 250 ° C. to about 550 ° C., an olefin partial pressure of about 3 psia to about 100 psia, and a total pressure of about 15 to about 100 psia, and about 1 ~ 100hr^-1Olefin-based WHSV is contacted with such a catalyst in a reactor. Preferred isomerization conditions are about 300 ° C. to about 425 ° C., atmospheric pressure, about 2 to about 40 hours.^-1This is WHSV based on olefins.
For mixed feeds, depending on the desired product mixture, the reaction conditions of the isomerization process between pentene and butene can be used.
The following examples further illustrate the invention. Percentages are given in parts by weight (pbw), weight percent, moles or equivalents.
The X-ray diffraction pattern of the zeolite prepared in the example was measured. The radiation was copper K-alpha doublet. The peak height (I) and its position as a function of 2 theta were read from the spectrometer chart. The sheeter is the angle of Bragg. These readings were used to calculate relative strength and interplanar voids according to established conventions. The results obtained were compared with those resulting from a known ferrierite sample. The clear characteristics of the XRD spectrum of ferrierite made by our method also indicate that these phases are pure.
The surface area of the ferrierite sample was measured by modifying ASTM test method D3663-92. This method uses a modified gas adsorption technique (BET) for surface area measurement as described by Brunauer, Emett and Teller. The ferrierite sample containing the template was calcined in air at 500 ° C. for 3 hours to remove the template before measuring the surface area of the ferrierite sample. The sample was degassed by heating to 350 ° C. in vacuum to remove adsorbed vapor and then cooled to liquid nitrogen temperature. The amount of nitrogen adsorbed at low pressure is determined by measuring a pressure difference after introducing a fixed volume of nitrogen into the sample. Under these conditions, nitrogen was adsorbed into the zeolite micropores. Volumetric adsorption measurements were performed at P / Po pressure levels between 0.02 and 0.05. The amount of adsorbed nitrogen is calculated using the BET equation.
Example 1
This example illustrates the preparation of ferrierite having a high silica to alumina molar ratio, high purity, and high surface area according to the present invention. 21.6 g of hydrated aluminum sulfate was dissolved in 1000.2 g of deionized water. To this solution, 109.2 g of pyridine was added followed by 46.9 g of 97% sulfuric acid. 28.7% SiO₂8.9% Na₂This solution was mixed well before adding 47.2 g of sodium silicate with O, equilibrium water composition. The resulting gel was mixed for 30 minutes and then placed in a stirring autoclave and heated to 170 ° C. for 24 hours. The molar composition of the autoclave filling is:
1.0 Al₂O_Three/2.7 Na₂O / 60 SiO₂/ 1938 H₂O / 36.7 Pyridine
Met.
OH^-/ SiO₂The filling ratio was 0.09.
The resulting solid product was cooled to room temperature, filtered and separated from the liquid, washed with 33 ml of 150 ° F. water per gram of product and dried at 250 ° F. Part of the product was subjected to X-ray analysis and found to be pure ferrierite. After calcination at 1000 ° F for 5 hours to remove pyridine, measure the surface area of the product and measure 393m²The result of / g was obtained. The product is 53 SiO₂/ Al₂O_ThreeAnd 1.24% Na₂Contains O anhydride.
The calcined product was then ion exchanged with an aqueous ammonium nitrate solution (4 parts by weight ammonium nitrate per part by weight ferrierite) to convert to the ammonium form of ferrierite. The ammonium ion exchange was treated at 200 ° F. for 2 hours. The ion exchanged product was separated from the liquor by filtration, washed with 3 gallons of 150 ° F. water per pound of ferrierite and dried at 250 ° F. Measure the surface area of the product, 398m²A value of / g was obtained. Analyzing the dry ammonium exchange product, 55: 1 SiO₂/ Al₂O_ThreeHaving a molar ratio of 139 ppm anhydrous Na₂Found to contain O.
A portion of the dried ammonium exchange ferrierite was compressed, crushed and sieved to 6-20 mesh particles. 6-20 mesh particles were calcined in flowing air at 500 ° C. for 2 hours to convert to ferrierite hydrogen form.
Example 2
21.0 g of hydrated aluminum sulfate was dissolved in 918.2 g of deionized water. To this solution was added 123.1 g pyridine and 54.6 g 97% sulfuric acid. After this solution was mixed well, 533.5 g of sodium silicate (same composition as Example 1) was added. The resulting gel was mixed well for 30 minutes and filled into a stirred autoclave.
The autoclave was heated at 170 ° C. for 24 hours. The resulting solid product was cooled to room temperature, filtered and separated from the liquid, washed with 33 ml of 150 ° F. water per gram of product and dried at 250 ° F. A part of the product was subjected to X-ray analysis and found to be pure ferrierite. Calcination at 1000 ° F for 5 hours to remove pyridine, product surface area 392m²measured to be / g. The molar composition of autoclave filling is:
1.0 Al₂O_Three/3.15 Na₂O / 70 SiO₂/ 1938 H₂O / 42.8 Pyridine
Met. OH^-/ SiO₂The filling ratio was 0.09. The product is 65.1 SiO₂/ Al₂O_ThreeAnd has a ratio of 1.34% Na₂Contains O anhydride.
Example 3
23.1 g of hydrated aluminum sulfate was added to 722.0 g of deionized water and mixed until dissolved. To this solution was added 86.6 g pyridine and 81.8 g 97% sulfuric acid. After the solution was mixed well, 736.4 g of sodium silicate (same composition as in Example 1) was added and the resulting gel was mixed well for 30 minutes. The gel was filled into a stirring autoclave and heated to 150 ° C. for 72 hours. The molar composition of autoclave filling is:
1.0 Al₂O_Three/3.13 Na₂O / 87.2 SiO₂/1661.5 H₂O / 27.1 pyridine. Filling OH^-/ SiO₂The ratio was 0.072.
The resulting solid product was cooled to room temperature, filtered and separated from the liquid, washed with 33 ml of 150 ° F. water per gram of product and dried at 250 ° F. A part of the product was subjected to X-ray analysis and found to be pure ferrierite. After calcination at 1000 ° F for 5 hours to remove pyridine, measure the surface area of the product and measure 391m²The result of / g was obtained. The product is 78.0 SiO₂/ Al₂O_ThreeHas a ratio and 1.6% Na₂Had O anhydride.
The calcined product was then ion exchanged with an aqueous ammonium nitrate solution (2 parts by weight ammonium nitrate per part by weight ferrierite) to convert it to the ammonium form of ferrierite. The ammonium ion exchange was treated at 200 ° F. for 2 hours. The ion exchanged product was separated from the liquor by filtration, washed with 3 gallons of 150 ° F. water per pound of ferrierite and dried at 250 ° F. Measure the surface area of the product, 395m²A value of / g was obtained. The dry ammonium exchange product was analyzed and 78: 1 SiO₂/ Al₂O_ThreeHaving a molar ratio of 92 ppm Na₂Found to contain O anhydride.
A portion of the dried ammonium exchange ferrierite was compressed, crushed and sieved to 6-20 mesh particles. The 6-20 mesh particles were calcined in flowing air at 500 ° C. for 2 hours to convert to the ferrilite hydrogen form.
Example 4
38.4 g of hydrated aluminum sulfate was dissolved in 1470.3 g of deionized water. To this solution was added 158.8 g pyridine and 150.3 g 97% sulfuric acid. This solution was mixed well before adding 1307.2 g of sodium silicate (same composition as in Example 1). The resulting gel was mixed well for 30 minutes and filled into a stirred autoclave. The autoclave was heated at 150 ° C. for 72 hours. The resulting solid product was cooled to room temperature, filtered and separated from the liquid, washed with 33 ml of 150 ° F. water per gram of product and dried at 250 ° F. A part of the product was subjected to X-ray analysis and found to be pure ferrierite. After calcination at 1000 ° F for 5 hours to remove pyridine, the product surface area is 389m²measured to be / g. The molar composition of autoclave filling is:
1.0 Al₂O_Three/2.81 Na₂O / 93.5 SiO₂/ 1938 H₂O / 30 pyridine
Met. OH^-/ SiO₂The filling ratio was 0.06. The product is 84.4 SiO₂/ Al₂O_ThreeAnd has a ratio of 1.28% Na₂Contains O anhydride.
Example 5
20.5 g of hydrated aluminum sulfate was added to 914.1 g of deionized water and mixed to dissolve. To this solution was added 98.3 g pyridine and 35.1 g caustic soda. To this solution, 83.2 g of sodium sulfate was added and dissolved. After mixing well, 498.8g of 40% silica sol (composition 40% SiO₂, 0.5% Na₂O, equilibrated water) was added. The resulting gel was mixed well for 30 minutes before filling the stirred autoclave. The autoclave was heated at 170 ° C. for 36 hours. The resulting solid product was cooled to room temperature, filtered and separated from the liquid, washed with 33 ml of 150 ° F. water per gram of product and dried at 250 ° F. A part of the product was subjected to X-ray analysis and found to be pure ferrierite. After calcination at 1000 ° F for 5 hours to remove pyridine, the product surface area is 351m²measured to be / g. The molar composition of autoclave filling is:
1.0 Al₂O_Three/4.3 Na₂O / 93.5 SiO₂/ 1938 H₂O / 22.5 Na₂SO_Four/ 30 pyridine
Met. OH^-/ SiO₂The filling ratio was 0.092. The product is 77.2 SiO₂/ Al₂O_ThreeHaving a molar ratio of 1.64% Na₂Contains O anhydride.
Example 6
This example illustrates the product formed when not following the invention. 24.4 g of hydrated aluminum sulfate was dissolved in 757.8 g of deionized water. To this solution was added 92.9 g 97% sulfuric acid and 91.0 g pyridine. The solution was mixed well before adding 774.1 g of sodium silicate (same composition as in Example 1). The resulting gel was mixed for 30 minutes and filled into a stirred autoclave. The autoclave was heated at 150 ° C. for 72 hours. The resulting solid product was cooled to room temperature, filtered and separated from the liquid, washed with 33 ml of 150 ° F. water per gram of product and dried at 250 ° F. A part of the product was subjected to X-ray analysis and found to be amorphous. The molar composition of autoclave filling is:
1.0 Al₂O_Three/1.53 Na₂O / 87.2 SiO₂/1661.5 H₂O / 27.1 Pyridine
Met. OH of this formulation^-/ SiO₂The ratio was 0.035. This is below the amount required according to the present invention.
Example 7
This is another example of a product formed when not in accordance with the present invention. 23.4 g of hydrated aluminum sulfate was dissolved in 747.5 g of deionized water. To this solution was added 71.1 g 97% sulfuric acid and 87.5 g pyridine. The solution was mixed well before adding 720.6 g sodium silicate (same composition as in Example 1). The resulting gel was filled into a stirred autoclave and heated at 150 ° C. for 72 hours. The resulting solid product was cooled to room temperature, filtered and separated from the liquid, washed with 33 ml of 150 ° F. water per gram of product and dried at 250 ° F. A portion of the product was subjected to X-ray analysis and found to contain some ferrierite contaminated with magadiite-like material (s). The molar composition of autoclave filling is:
1.0 Al₂O_Three/5.1 Na₂O / 84.4 SiO₂/1661.5 H₂O / 27.1 Pyridine
Met. OH of this formulation^-/ SiO₂The ratio was 0.12. This ratio is very high relative to the molar ratio of silica and alumina used in this example.
Example 8
This is an example of the resulting product when not in accordance with the present invention. 20.5 g of hydrated aluminum sulfate was dissolved in 899.3 g of deionized water. To this solution was added 84.5 g pyridine and 64.0 g 50% caustic soda. 81.5 g of sodium sulfate was then added to the well mixed solution. The mixture was stirred until the solid dissolved. Finally, 500.3 g of 40% silica sol (same composition as Example 5) was added and the resulting gel was mixed for 30 minutes. The gel was charged into a stirred autoclave and heated at 170 ° C. for 36 hours. The resulting solid product was cooled to room temperature, filtered and separated from the liquid, washed with 33 ml of 150 ° F. water per gram of product and dried at 250 ° F. A portion of the product was subjected to X-ray analysis and found to contain some ferrierite as well as quartz and other crystalline silica phases. After calcination at 1000 ° F for 5 hours to remove pyridine, the product is 254 m²It had a surface area of / g. The molar composition of autoclave filling is:
1.0 Al₂O_Three/9.35 Na₂O / 93.5 SiO₂/ 1938 H₂O / 19.1 Na2SO4 / 30 Pyridine
Met. The product is 65.8 SiO₂/ Al₂O_ThreeAnd 2.23% Na₂O, anhydrous. OH of this formulation^-/ SiO₂The ratio of was 0.2. This ratio is outside the range required for the present invention.
Example 9
This is an example in which ferrierite was prepared using piperidine instead of pyridine as a template. 21.5 g of hydrated aluminum sulfate was dissolved in 995.3 g of deionized water. To this solution was added 116.8 g piperidine and 46.5 g 97% sulfuric acid. The solution was mixed well and 470.0 g of sodium silicate (same composition as Example 1) was added. The resulting gel is mixed well for 30 minutes and filled into a stirred autoclave. The autoclave was heated at 170 ° C. for 36 hours. The resulting solid product was processed as described in the previous examples and found to be a magadiet contaminated ferrierite. Product surface area is 322m²/ g. The molar composition of autoclave filling is:
1.0 Al₂O_Three/2.7 Na₂O / 60 SiO₂/ 1938 H₂O / 36.7 Pyridine
Met.
Filling OH^-/ SiO₂The ratio was 0.09. The product is 37.6 SiO₂/ Al₂O_ThreeAnd 0.78% anhydrous Na₂O was included. Contaminated ferrierite was formed in this example because piperidine was directly substituted for pyridine as a template in the formulation.
Example 10
This example is in accordance with the teachings of the present invention and describes a more efficient synthesis of ferrierite having a high silica to alumina molar ratio, high purity, and high surface area. 78.5 g of hydrated aluminum sulfate was dissolved in 1235.4 g of deionized water. To this solution was added 166.5 g 97% sulfuric acid and 1681.0 g sodium silicate (same composition as Example 1). After the resulting gel was mixed well for 30 minutes, 208.6 g of pyridine was added followed by remixing for 30 minutes. The final mixture was placed in a stirring autoclave and heated to 170 ° C. for 24 hours. The molar composition of autoclave filling is:
1.0 Al₂O_Three/2.7 Na₂O / 60 SiO₂/ 975 H₂O / 19.7 Pyridine
Met.
OH^-/ SiO₂The filling ratio was 0.09. The resulting solid product was treated as described in the previous examples and 388 m²It was found to be pure ferrierite with a surface area of / g. The product is 57: 1 SiO₂/ Al₂O_ThreeAnd 1.97% anhydrous Na₂O was included.
The calcined product was then ion exchanged with an aqueous ammonium nitrate solution (2 parts by weight ammonium nitrate per part by weight ferrierite) to convert it to the ammonium form of ferrierite. The ammonium ion exchange was treated at 200 ° F. for 2 hours. The ion exchanged product was separated from the liquor by filtration, washed with 3 gallons of 150 ° F. water per pound of ferrierite and dried at 250 ° F. The surface area of the product is 369m²measured to be / g. The dried ammonium exchange product was analyzed and 62: 1 SiO₂/ Al₂O_ThreeHaving a molar ratio of 480 ppm anhydrous Na₂Found to contain O. The product had an adsorption capacity of 7.3 g of n-hexane per 100 g of zeolite.
A portion of the dried ammonium exchange ferrierite was compressed, crushed and sieved to 6-20 mesh particles. 6-20 mesh particles were calcined at 500 ° C. for 2 hours in a stream of air to convert to ferrilite hydrogen form.
Example 11
This example is in accordance with the teachings of the present invention, but shows that a certain minimum amount of pyridine is necessary to crystallize ferrierite having a high ratio, high purity, and high surface area. 22.4 g of hydrated aluminum sulfate was dissolved in 1040.2 g of deionized water. To this solution was added 34.5 g of pyridine and 48.7 g of 97% sulfuric acid. This solution was mixed well. 491.0 g of sodium silicate (same composition as in Example 1) was added to this solution and the resulting gel was mixed well for 30 minutes. The gel was placed in a stirring autoclave and heated at 170 ° C. for 24 hours. The resulting solid product was processed as described in the previous examples and found to be amorphous. The molar composition of autoclave filling is:
1.0 Al₂O_Three/2.7 Na₂O / 60 SiO₂/ 1938 H₂O / 15.4 Pyridine
Met.
Filling OH^-/ SiO₂The ratio was 0.09.
Example 12
This example demonstrates the effect of seeding the synthesis mixture with crystalline ferrierite in the production of high ratio, high purity, high surface area ferrierite in accordance with the teachings of the present invention. 23.1 g of hydrated aluminum sulfate was dissolved in 1046.4 g of deionized water. To this solution, 49.0 g pyridine and 37.3 g 97% sulfuric acid were added with good mixing. 7.3 g of high ratio, high purity ferrierite made according to the present invention was added to the solution and well dispersed. To this slurry 494.2 g of sodium silicate (same composition as in Example 1) was added and the resulting gel was mixed well for 30 minutes. The gel was placed in a stirred autoclave and heated at 170 ° C. for 24 hours. The resulting solid product was processed as described in the previous examples and 419 m²It was found to be a high-ratio, high-purity ferrierite with a surface area of / g. The molar composition of autoclave filling is:
1.0 Al₂O_Three/2.7 Na₂O / 60 SiO₂/ 1938 H₂O / 12 Pyridine
OH^-/ Al₂O_ThreeThe filling ratio was 0.09. The product is 57.2 SiO₂/ Al₂O_ThreeAnd 1.93% anhydrous Na₂O was included.
Example 13
This example describes the additional advantages of a high ratio, high purity, high surface area ferrierite made in accordance with the present invention. The product is ion exchanged prior to the calcination treatment to remove the pyridine trapped in the zeolite. 200g NH_FourNO_ThreeWas dissolved in 833.3 g of deionized water to prepare a 3N ammonium nitrate solution. To this solution was added 205.3 g (LOI = 51.29%) of a filter cake made according to Example 10 and synthesized into a high ratio, high purity ferrierite. The solid was mixed well and dispersed, and the slurry was heated at 200 ° F. for 2 hours. The resulting solid product was cooled to room temperature, separated from the liquid by filtration, washed with 25 ml of 150 ° F. water per gram of product, and dried at 250 ° F. The elemental composition of the product was analyzed using atomic absorption spectroscopy. The product is 61.6 SiO₂/ Al₂O_Three, And 2700 ppm Na₂O was included. After calcining to remove pyridine at 1000 ° F for 5 hours, the product is 385m²had a surface area of / g.
Example 14
Samples of ammonium ferrierite were prepared by the method outlined in US-A-4,251,499, 4,795,623, and 4,942,027. The sample was compressed, crushed and sieved to 6-20 mesh particles. The particles are then calcined for 2 hours at 500 ° C²An H-ferrierite catalyst having a surface area of / g and a silica to alumina molar ratio of 19: 1 was prepared.
Example 15
A sample of potassium / sodium ferrierite having a 16: 1 silica / alumina molar ratio was obtained from TOSOH. This material was ammonium ion-exchanged and converted to 6-20 mesh particles as described above. Then the particles are 323m²It was calcined at 500 ° C. for 2 hours to produce a catalyst with a surface area of / g and a silica to alumina molar ratio of 16: 1.
Example 16
A sample of ammonium ferrierite was prepared by the method outlined in Example 2 of EP-A-501,577. OH with autoclave filling^-/ SiO₂The ratio was 0.16. Ammonium ferrierite was compressed, crushed and sieved to 6-20 mesh particles. These particles are then calcined at 500 ° C. for 2 hours to give 326 m²A ferrierite hydrogen (H-ferrierite) catalyst having a surface area of / g and a silica to alumina bulk molar ratio of 87: 1 was prepared. After crystallization and washing, the sample contained about 5-10% non-ferrierite impurities. These impurity concentrations decreased (but did not disappear) with the ammonium ion exchange of the sample and with calcination.
Example 17
This example illustrates a method for preparing an extruded ferrierite catalyst useful for olefin isomerization of the backbone.
645 g ammonium-ferrierite (5.4% LOI) prepared by the method outlined in Example 10 and 91 g CATAPAL® D alumina (25.% LOI) were charged to a Lancaster Malar mixer. Alumina was mixed with ferrierite for 5 minutes, during which 152 ml of deionized water was added. A mixture of 6.8 g glacial acetic acid, 7.0 g citric acid, and 152 ml deionized water was slowly added to the muller to promote mastication of the alumina. The mixture was triturated for 10 minutes. Thereafter, 0.20 g tetraminepalladium nitrate in 153 g deionized water was added slowly as the mixture was milled for an additional 5 minutes. 10 g of METHOCEL® F 4M hydroxypropylmethylcellulose was added and an additional zeolite / alumina mixture was added and mixed and ground for 15 minutes. The extrusion mixture had a LOI of 43.5%. The 90:10 zeolite / alumina mixture was transferred to a 2.25 inch Bonnot extruder and extruded using a stainless steel die plate with 1/16 "holes.
The extrudate was dried at 125 ° C. for 16 hours and then calcined in a stream of air at a maximum temperature of 500 ° C. for 2 hours. Calcination, extrudate is 364m²It had a surface area of / g.
Isomerization of olefin skeleton
A stainless steel tube 1 inch outer diameter, 0.6 inch inner diameter, and 26 inches long was used as the reactor. The thermowell was extended 20 inches from the top of the tube. To charge the reactor, the glass wool stopper was first slipped over the reactor tube over the thermowell, until it hits the bottom of the tube. Silicon carbide (20 mesh) was added to a depth of about 6 inches. A small amount of glass wool stopper was placed on top of this. Approximately 4g of catalyst particles mixed with about 60g of new silicon carbide (60-80 mesh), 6-20 mesh (or small extrudate) was added in two portions so that the catalyst particles were evenly distributed . The catalyst bed was typically about 10 inches long. Another piece of glass wool was added to the top of the catalyst and the reactor was covered with 20 mesh silicon carbide followed by the last plug of glass wool. A multi-point thermocouple was inserted into the thermowell and placed in place so that temperatures at three different locations in the high, low, and catalyst beds could be monitored. The reactor was inverted and placed in a temperature controlled furnace.
The feed used was 1-butene obtained from Scott Specialty Gases with a 1-butene content of 99.2% by weight or more. 1-butene was fed to the reactor in the gas phase.
To begin operating the reactor, all were initially heated to the desired operating temperature for 4 hours under a nitrogen stream and maintained at the operating temperature for 2 hours. After this pretreatment, shut off the nitrogen stream and add 1-butene at a rate of 36 g / hr, 9.0 hr^-1The desired weight hourly space velocity was given. The reactor was operated at the outlet with a pressure of 3 psig and a temperature of 430 ° C.
Regeneration
After the catalyst was allowed to act in the above isomerization process, it was observed that the catalyst turned black due to the deposition of carbonaceous material (coke) consisting of about 10-20% by weight. Each catalyst was removed from the test reactor and weighed. To prove that the catalyst can be regenerated, the two tested catalysts were reloaded separately into two test reactors and regenerated as follows. Each reactor was pressurized to 90 psig and started to flow standard 6 l / hr air. Samples were heated according to the following controlled heating procedure: ramped from 25 ° C to 125 ° C at 10 ° C per minute; held at 125 ° C for 30 minutes; ramped from 125 ° C to 350 ° C at 2 ° C per minute; Raise from 350 ° C to 470 ° C at 1 ° C for 1 minute and hold at 470 ° C for 24 hours. Thereafter, the reactor was cooled, and the regenerated catalyst was taken out. Substantially complete catalyst regeneration was confirmed by the disappearance of the unregenerated black catalyst color. The catalyst was weighed and coke loss was measured.
Calculation
Conversion and selectivity are calculated for each sample throughout the test run. Conversion and selectivity calculations are therefore affected by the concentrations of butene-1 (B1), butene-2 (B2), and isobutylene (IB1) in the feed stream (FD) and effluent stream (EFF). The conversion rate is calculated as follows:

Selectivity is calculated as follows:

And the yield is calculated as follows:

Table 1 shows the results of the isomerization effect of the olefin backbone obtained by testing several catalysts prepared in the above examples. This table shows the running time of the catalyst in the isomerization test, that is, the time from the start of running until the concentration of methyl-branched olefin (isobutylene in these tests) in the product decreases to 36 wt% after reaching the peak concentration. Is shown. Some of the catalysts tested (Examples 14 and 15) never reached the isobutylene concentration in this high product. The catalyst of the present invention was able to achieve the longest running life. Long running life was sustained and in some cases rather increased by catalyst regeneration.
In commercial operation, it is desirable to operate the catalyst until the concentration of isobutylene in the product is reduced to 20 wt% or less before regenerating the catalyst. The sample prepared by the method described in Example 1 showed a running life of 603 hours when run until the isobutylene content in the product dropped to 20 wt%. Longer running life could also be achieved by working with a low hourly weight space velocity of 1-butene, WHSV. Increased travel life can also be obtained by diluting the olefin content in the feed, often with less reactive gas present in the feed of olefin skeletal isomerization. Suitable diluent gases include, for example, propane, butane, pentane, nitrogen and hydrogen. The use of these gases helps to reduce the partial pressure of the olefin to be isomerized and provides a high reported selectivity for branched olefins. Although the use of a diluent gas can increase the running life and selectivity to isobutylene of the catalyst of the present invention, the presence of the diluent gas is the type reported in DE-A-3,000,650 and US-A-5,043,523. More than the report on non-ferrierite catalysts, there is no requirement to obtain a long running life at a certain conversion rate and high selectivity.
Table 1 also shows the selectivity of the various catalysts at 40% conversion, 45% conversion, and 50% conversion, and the highest concentration (weight percent) of isobutylene in the product during the test.
As can be seen from Table 1, the catalysts of the present invention (Examples 1, 3 and 17) have a low silica to alumina molar ratio (Examples 14 and 15) and / or a low surface area (Examples 15 and 16). When compared to the sample, the highest selectivity is obtained at a certain conversion level and the highest isobutylene concentration in the product. Table 1 shows a high surface area and clearly shows a significant improvement in the isomerization behavior of the olefin skeleton obtained with catalysts made from high purity, high silica to alumina molar ratio ferrierite. . The catalyst made in Example 3 has a selectivity for isobutylene of 95% at 40% conversion. Almost 100% selectivity was obtained with the catalyst of the present invention at slightly lower conversion levels.
Example 3 gave a selectivity to 88% isobutylene under these test conditions at 45% conversion. Catalysts made with low silica to alumina molar ratio ferrierite (Examples 15 and 14) achieved 68% and 70% selectivity to isobutylene at 45% conversion. The catalyst of Example 16, made with a high silica / alumina molar ratio ferrierite, was 326 m.²With a surface area of / g, a selectivity to isobutylene of 79% was achieved at 45% conversion. All the catalysts prepared according to the present invention showed a selectivity to isobutylene of more than 83% with a conversion of 45%.
The advantage of the action of the high purity, high silica / alumina molar ratio ferrierite prepared according to the present invention is that it contains less total ferrierite relative to the extruded catalyst such as the catalyst made in Example 17. Even when diluted with a binder (Example 17), it is to enable superior performance over Examples 14, 15, and 16. The advantages of these actions were maintained even if this ferrierite catalyst was regenerated many times.
The crystal ferrierite samples prepared in the examples were analyzed using a transmission electron microscope, TEM, scanning electron microscope, and SEM at a magnification as high as 21,200X magnification. FIG. 1 is a TEM micrograph of ferrierite prepared by the method of Example 1. Micrographs were taken at 21,000X magnification. The ferrierite crystals of the present invention exhibit a small plate format that is well-morphologically contoured; one dimension of the crystal has an average diameter of about 0.1 μm. The average of the second largest diameter is about 0.8 μm and the average of the largest diameter is about 1.1 μm. Some of the crystals prepared in Example 1 had a maximum diameter of about 2 μm.
The morphology of the ferrierite made in the present invention is a different form than that of the ferrierite made in Example 14, and the ferrierite of Example 14 is smaller, more round, and has an irregular crystalline shape. Looks like. FIG. 2 is a TEM micrograph of ferrierite prepared by the method of Example 14. Micrographs were taken at 21,200X magnification. The average maximum diameter of the ferrierite crystals made in Example 14 was about 0.2 μm. Some of the crystals were about 0.1 μm or less in all three dimensions.
The crystal morphology of ferrierite prepared in the present invention is also different from that of microcrystalline ZSM-35 (ferrierite isotype) prepared by the method of US-A-3,392,466. Microcrystalline ZSM-35 is reported to have very small particles with diameters ranging from 0.005 μm to 0.1 μm.
The relatively large, small tabular morphology of the crystals in the present invention, the high surface area of ferrierite, and the high silica / alumina molar ratio are at a fixed conversion level when these high purity ferrierite catalysts process butylene-containing feedstocks. This makes it possible to show excellent selectivity for isobutylene. These identical ferrierite properties allow the catalyst to work equally well with other C4-C10 olefin feeds.

Claims (16)

X-ray diffraction pattern of ferrierite and in anhydrous state
1-3 R: 0.5-0.9 M ₂ O: Al ₂ O ₃ : 40-500 SiO ₂
A crystalline aluminosilicate having a composition of (R is pyridine, and M is an alkali metal), characterized in that it has a surface area of at least 350 m ² / g and is essentially a crystalline phase of ferrierite Aluminosilicate. The crystalline aluminosilicate of claim 1, having a surface area of at least 370 m ² / g . The crystalline aluminosilicate according to claim 1, having a surface area of up to 450 m ² / g . In an anhydrous state,
1-3 R: 0.5-0.9 M ₂ O: Al ₂ O ₃ : 50-200 SiO ₂
The crystalline aluminosilicate according to any one of claims 1 to 3, having a composition of: In an anhydrous state,
1-3 R: 0.5-0.9 M ₂ O: Al ₂ O ₃ : 65-100 SiO ₂
The crystalline aluminosilicate according to any one of claims 1 to 4, having a composition of: 6. The crystalline aluminosilicate according to any one of claims 1 to 5, wherein one dimension of the crystals is on average 0.2 μm or less and the other two dimensions are on average greater than 0.6 μm . A method for producing ferrierite crystalline aluminosilicate, comprising:
providing a mixture containing an alkali metal source, silica, alumina, and pyridine, said mixture having the following composition in moles:
Al ₂ O ₃ : 60-500 SiO ₂ : 10-40 R: 1.5-4 M ₂ O: 950-2000 H ₂ O
(Where R is pyridine, M is an alkali metal, and the alkali metal source and silica are present in an amount of 0.05 to 0.15 moles of OH ⁻ for each mole of SiO ₂ )
b. heating the mixture to a temperature between 140 ° C and 180 ° C;
c. collect ferrierite,
Said manufacturing method characterized by the above-mentioned. 8. The method of claim 7, wherein the mixture further comprises ferrierite seeds to promote ferrierite nucleation and / or growth. Per mole of SiO _2, 0.05-0.11 moles of OH ^- are present, the method according to claim 7 or 8. 10. Ferrierite crystalline aluminosilicate produced by the method claimed in any one of claims 7-9. A method of producing ferrierite hydrogen having a surface area of at least 350 m ² / g , a silica to alumina ratio of at least 50, and a crystalline phase of ferrierite essentially,
d. removing at least a portion of the pyridine present in the ferrierite claimed in any one of claims 1-6 and 10 by heating to a temperature of 500-526 ° C. Get the light
e. contacting the calcined-ferrierite with an ammonium-ion source to provide an ammonium-ion exchanged ferrierite; and
f. The above production method, wherein the ammonium-ion exchange ferrierite is calcined at a temperature of 200 ° C to 700 ° C. 12. Ferrierite hydrogen produced by the method of claim 11 having a surface area of at least 350 m < ² > / g , a ratio of silica to alumina of at least 50, and essentially a crystalline phase of ferrierite. A process for the structural isomerization of a linear olefin of at least 4 carbon atoms into the corresponding methyl-branched isoolefin, wherein at least one said linear olefin is reacted at a temperature of 200 ° C to 650 ° C. Characterized in that the containing hydrocarbon feed fluid is contacted with an isomerization catalyst containing ferrierite hydrogen having a surface area greater than 350 m ² / g, a silica to alumina ratio greater than 50, and a phase of ferrierite crystals essentially. And how to. 14. A process according to claim 13, wherein the isomerization catalyst is ferrierite hydrogen having a surface area of at least 370 m < ² > / g . 15. A process according to claim 13 or 14, wherein the isomerization catalyst is ferrierite hydrogen having a silica to alumina molar ratio of 60: 1 or greater. 16. A method according to any one of claims 13 to 15, wherein the ferrierite hydrogen is as described in claim 12.

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